For the same control.TransferFunction() sys, if I called with python version control.pzmap(), it reports that

TypeError: 'module' object is not callable

If called control.matlab.pzmap() it does plot the poles but not zeros. I checked the code that when plotting zeros, facecolors is set to 'none'.

How can I change the color back? I think it's more reasonable to set a proper color for this line.

Thanks.